Solve Each Equation or Inequality Over the Indicated Interval $\cos 2 \theta-\cos \theta=0, \quad\left[0^{\circ}, 360^{\circ}\right)$

Solve each equation or inequality over the indicated interval.
- $\cos 2 \theta-\cos \theta=0, \quad\left[0^{\circ}, 360^{\circ}\right)$